A General Medical Practitioner (GP) auscultates using a stethoscope to listen to heart sounds for finding abnormalities, if any, in the patient's heart. To make a reliable diagnosis a GP needs to be skilled and needs a good stethoscope. An independent study (IEEE TBME, 2007) indicated that about eighty percent of the patients referred by GPs to specialists after evaluation using stethoscopes are found to be normal. This shows that it is difficult to make accurate diagnosis using a stethoscope.
Digital stethoscopes are available in the market today. They reduce ambient noise heard by the user by filtering, enhance the heart sounds, store the sounds and some also display a visual representation of them.